This invention relates to a novel process for the production of allergen-containing extracts and to preparations produced therefrom suitable for the diagnosis of sensitizing antigens and for the specific desensitization of allergic persons.
It has long been known that many persons show allergic reactions upon contact with certain naturally occurring materials. Carriers of such allergenically active agents include pollens, seeds, epithelia, especially animal hairs, dusts, especially house dust, insects, and fungi.
Clinical experience has shown that allergic reactions can be lessened by subcutaneous injections of extracts of the substances causing the allergy. Heretofore, aqueous liquids, such as physiological NaCl solution, weakly alkaline, optionally buffered salt solutions, and dilutions of alcohol in physiological Nacl solutions have been employed for the production of such allergenic extracts or preparations in general, sometimes after previously degreasing the allergen-containing starting material with ether.
Generally, the thus-obtained solutions, after removal of the solid components, are filtered aseptically and injected suitably diluted into the patients for desensitizing purposes. The use of these aqueous extracts requires a larger number of injections with gradually increasing amounts of allergen. Therefore, the use of semidepot preparations is advantageous, permitting a substantial reduction of the number of injections required and simultaneously lessening danger of excessive reaction. The literature has described extraction processes for the production of such semidepot preparations using aqueous solutions of heterocyclic tertiary amines, especially pyridine, lutidine and quincline.
The binding of the extracted allergens is accomplished as an aluminum hydroxide adsorbate by adding alum solution to the alkaline extract. The thus-formed precipitate containing the active substances is resuspended in a physiological solution after removal of the solvent and after repeated washing. However, these semidepot preparations can be utilized only for the treatment of patients and not for diagnostic purposes. Such preparations are, for example, described in the U.S. Pat. Nos. 3,148,121 and 3,148,122.